694 research outputs found
Vortex Flows in the Solar Chromosphere -- I. Automatic detection method
Solar "magnetic tornadoes" are produced by rotating magnetic field structures
that extend from the upper convection zone and the photosphere to the corona of
the Sun. Recent studies show that such rotating features are an integral part
of atmospheric dynamics and occur on a large range of spatial scales. A
systematic statistical study of magnetic tornadoes is a necessary next step
towards understanding their formation and their role for the mass and energy
transport in the solar atmosphere. For this purpose, we have developed a new
automatic detection method for chromospheric swirls, i.e. the observable
signature of solar tornadoes or, more generally, chromospheric vortex flows and
rotating motions. Unlike the previous studies that relied on visual
inspections, our new method combines a line integral convolution (LIC) imaging
technique and a scalar quantity which represents a vortex flow on a
two-dimensional plane. We have tested two detection algorithms, based on the
enhanced vorticity and vorticity strength quantities, by applying them to 3D
numerical simulations of the solar atmosphere with CO5BOLD. We conclude that
the vorticity strength method is superior compared to the enhanced vorticity
method in all aspects. Applying the method to a numerical simulation of the
solar atmosphere revealed very abundant small-scale, short-lived chromospheric
vortex flows that had not been found by visual inspection before.Comment: 12 pages, 9 figures, accepted for publication in A&
Critical Behavior in Doping-Driven MetalInsulator Transition on Single-Crystalline Organic Mott-FET
We present the carrier transport properties in the vicinity of a
doping-driven Mott transition observed at a field-effect transistor (FET)
channel using a single crystal of the typical two-dimensional organic Mott
insulator -(BEDT-TTF)CuN(CN)Cl (-Cl).The FET shows a
continuous metalinsulator transition (MIT) as electrostatic doping proceeds.
The phase transition appears to involve two-step crossovers, one in Hall
measurement and the other in conductivity measurement. The crossover in
conductivity occurs around the conductance quantum , and hence is not
associated with "bad metal" behavior, which is in stark contrast to the MIT in
half-filled organic Mott insulators or that in doped inorganic Mott insulators.
Through in-depth scaling analysis of the conductivity, it is found that the
above carrier transport properties in the vicinity of the MIT can be described
by a high-temperature Mott quantum critical crossover, which is theoretically
argued to be a ubiquitous feature of various types of Mott transitions. [This
document is the unedited Authors' version of a Submitted Work that was
subsequently accepted for publication in Nano Letters, copyright \copyright
American Chemical Society after peer review. To access the final edited and
published work see http://dx.doi.org/10.1021/acs.nanolett.6b03817]Comment: 40 pages, 16 figures in Nano Letters, ASAP (2017
A Study on Route Choice Model in the Case of Recreational Trip
This study aims to suggest an appropriate road improvement planning for regional exchange, with a view to regard recreational trip as main behavior of regional exchange. We have clarifyied how the facilities which will contribute to regional development influence route choice. This paper reported the results of the evaluation concerning the attractiveness of recreational facilities which influence route choice in case of a recreational trip, by quantification theory I, using the questionnaire data carried out in Fukui Prefectural TAN-NAN region. These results of analysis of attractive factors suggest that the model using the staying time has most applicable interpretation. However, further investigation on the grasp of the number of visitors is necessary
A Study on Route Choice Model in the Case of Recreational Trip
This study aims to suggest an appropriate road improvement planning for regional exchange, with a view to regard recreational trip as main behavior of regional exchange. We have clarifyied how the facilities which will contribute to regional development influence route choice. This paper reported the results of the evaluation concerning the attractiveness of recreational facilities which influence route choice in case of a recreational trip, by quantification theory I, using the questionnaire data carried out in Fukui Prefectural TAN-NAN region. These results of analysis of attractive factors suggest that the model using the staying time has most applicable interpretation. However, further investigation on the grasp of the number of visitors is necessary
Studies on Pheromones of Female Eri-Silk Moth, II. Preparation of Some Conjugated C₁₆-C₁₇ Alkadienals and Comparison of Them with the Pheromone by GLC
Article信州大学農学部紀要 20(1): 133-142(1983)departmental bulletin pape
Studies on Pheromones of Female Eri-Silk Moth, I. Preparation of C₆-C₁₁ 2-Alkenyl Triphenyiphosphonium Bromides
Article信州大学農学部紀要 20(1): 127-132(1983)departmental bulletin pape
X-ray Emissions from Three-dimensional Magnetohydrodynamic Coronal Accretion Flows
We calculate the radiation spectrum and its time variability of the black
hole accretion disk-corona system based on the three-dimensional
magnetohydrodynamic simulation. In explaining the spectral properties of active
galactic nuclei (AGNs), it is often assumed that they consist of a
geometrically thin, optically thick disk and hot, optically thin corona
surrounding the thin disk. As for a model of the corona, we adopt the
simulation data of three-dimensional, non-radiative MHD accretion flows
calculated by Kato and coworkers, while for a thin disk we assume a standard
type disk. We perform Monte Carlo radiative transfer simulations in the corona,
taking into account the Compton scattering of soft photons from the thin disk
by hot thermal electrons and coronal irradiation heating of the thin disk,
which emits blackbody radiation. By adjusting the density parameter of the MHD
coronal flow, we can produce the emergent spectra which are consistent with
those of typical Seyfert galaxies. Moreover, we find rapid time variability in
X-ray emission spectra, originating from the density fluctuation produced by
the magnetorotational instability in the MHD corona. The features of reflection
component including iron fluorescent line emission are also briefly discussed.Comment: accepted to Publications of the Astronomical Society of Japa
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